Various techniques are proposed which measure the radio wave state of radio communication, and collects the measuring results.
For example, Unexamined Japanese Patent Application KOKAI Publication No. 2002-232344 discloses a system which grasps a radio wave state (intensity of a received radio wave) in a communication region. This system includes radio wave state information collecting apparatuses each mounted in a vehicle or the like, and a management center which can radio-communicate with the radio wave state information collecting apparatuses. Each radio wave state information collecting apparatus generates reception intensity information representing the reception intensity of a radio wave transmitted from a radio base station (reception field intensity). Each radio wave state information collecting apparatus generates radio wave state information which includes the generated reception intensity information, point information representing the point of reception, and time information representing a current time, and transmits those information to the management center. The management center determines an area where the reception intensity represented by the reception intensity information based on the point information, and controls such that the distribution of reception intensities is displayed on a map so that a user can visually grasp the reception intensity.
Japanese Patent No. 3495025 discloses a system which collects data representing a reception intensity from a portable terminal. This system includes a plurality of portable terminals, a mobile communication network, and a radio wave measuring system. When a portable terminal within a survey target area transmits, an exchange for the mobile communication network collects reception level data and position data from the portable terminal, adds time information or the like, and transmits the resultant data to the radio wave measuring system. The radio wave measuring system analyzes the received information, and grasps the radio wave state of the target area in real time.
When a mobile communication undertaker or the like carries out a new mobile communication service in a region, the radio-wave propagation characteristic, such as the propagation loss, in that region needs to be predicted. At this time, reference may be made to data on other regions which has been measured using the above-described techniques or so.
The forgoing publications merely disclose the techniques of collecting data representing the radio wave state of a region which a communication business is actually carried out, and do not disclose a technique of predicting the radio-wave propagation characteristic of another arbitrary region using the collected data.